A tulip is a special type of joint which looks like a regular joint with a sack of marijuana on the end of it, which is made by sticking four rolling papers together in a large rectangle, placing an ample amount of weed in the centre, licking the edges and attaching it to the main shaft. I think. Hell I can roll but I can't roll these little bastards. Effects are very potent, and a tulip lasts a long time.
Be warned, though, if you've got a roller who is crap and/or stoned, there is a possible risk of the fucker spilling the entire thing on the floor.
Guy 1: "How mcuh weed we got left?"
Guy 2: "Quite a bit."
Guy 1: "Enough for... a tulip?"
Guy 2: "Hell yeah!"